1. Field of the invention
The present invention relates to a light-emitting device such as a semiconductor laser or a light-emitting diode adapted for use in optical communication system, optical integrated circuit, display or the like, and a method for producing said device.
2. Related Background Art
For high-speed transmission of information of a large amount, there is already known wavelength-multiplex optical communication. In such optical communication, the transmission of information is achieved by simultaneously passing, in an optical fiber, plural light beams of mutually different wavelengths, containing mutually independent signals. Also the light source employed in such optical communication is so constructed as to synthesize light beams, emitted from plural separate semiconductor lasers, in an optical synthesizer and to guide thus synthesized light beams into the optical fiber. Such optical synthesizer is described for example by Kojima et al., FPO, Vo.1, 4, No. 7, p. 45 (1979).
However such light source requires very cumbersome assembling and adjustment, as the plural semiconductor lasers and the optical synthesizer have to be aligned respectively with a high precision. For resolving the above-mentioned drawback, there can be conceived monolithic formation of plural light-emitting devices such as semiconductor lasers on a same substrate. The light-emitting devices thus formed facilitate alignment with the optical synthesizer, and enables compactization of the light source.
However such conventional light-emitting device involving plural light-emitting elements is difficult to prepare, and has limit in the extent of integration of devices. Particularly there are various difficulties in obtaining a high-density two-dimensional arrangement of the light-emitting devices.